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if __name__ == '__main__':
    # statements

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self.arr = nums

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letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g']
len(letters) # Returns length of array

## Common use
list = []
list.append((a,b))
list.sort() # nlogn

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dimensions = (200, 50) 

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student1 = {'gender': 'male', 'age': 18}
d = {} # d = dict()
d[0] = 1 # or d = {0:1}
d = defaultdict(int) # init with 0

# Update dict
if s in d:
    d[s] += 1 
else:
    d[s] = 1

## Java-like version
count += d.get(s-k,0)
d[s] = d.get(s,0) + 1

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new_set = {value1, value2, value2, ...}
new_set2 = set(value)

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# range(start, stop)
for i in range(1, 10): 
    print(i)

# range(stop) start from 0
for i in range(10):
    print(i)

# range(start, stop, step)
for i in range(0, 13, 5):
    print(i)

# travse backwards: https://www.tutorialspoint.com/backward-iteration-in-python
for i in range(len(nums)-1, -1, -1):

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if condition_1:
    statement_block_1 # Execute if condition_1 is True
elif condition_2:
    statement_block_2 # Execute if condition_1 is False & condition_2 is True
elif condition_3:
    statement_block 3 # Execute if condition_3 is True and 1 & 2 are False
else:
    statement_block_3 # Execute if previous conditions are all Falser 

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# While loop
num = 0
while num < 10:
    print(num)

# For loop
list = [1, 2, 3, 4, 5, 6]
for i in list:
    print(i)

for a, b, c in list:
    ## [[a,b,c],[1,2,3]]

for index, num in enumerate(nums)

for i in range(len(nums)):

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def function_name(parameters):
    expressions

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try:
    print(x)
except:
    print("Something went wrong")
finally: # finally will always be executed
    print("The 'try except' is finished")

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max(num1, num2)
sum(nums)
i**2 # i^2

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sum, num = 0,0
newlist = [0]
newlist = nums + [0]
newlist = [1] + [0] * k # [0:1, 0:0, 0:0]
newlist = list(rage(8))  # [0,1,..7]

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intervals = sorted(intervals, key = lambda x : x[0])
list.sort() # nlogn